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Engineering students are taught to approach the identification and solution of problems through design education, systems analysis, and other methods. These methodologies are applicable to other disciplines in relating problem solving to real world situations. (SK)

Sensing of indispensable amino acid (IAA) deficiency, an acute challenge to protein homeostasis, is demonstrated by rats as rejection of IAA-deficient diets within 20 min. The anterior piriform cortex (APC) of the brain in rats and birds is essential for this nutrient sensing, and is activated by IAA deficiency. Yet the mechanisms that sense and transduce IAA reduction to signaling in the APC, or indeed in any animal cells, are unknown. Because rejection of a deficient diet within 20 min is too rapid to be explained by transcription-derived signals, brain tissue was taken from rats after 20 min access to either a threonine-basal, -devoid, or -corrected diet and examined for proteins associated with early signaling of IAA deficiency in the yeast model. Western blots and immunohistochemistry showed that the phosphorylation of eukaryotic initiation factor 2-[alpha] (p-elF2[alpha][Ser51]) and translation of its downstream product, c-Jun, were increased (47%, P < 0.005, and 55%, P < 0.025, respectively) in APC from rats offered devoid, but not corrected diets, compared with those offered basal diets. This was not seen in other brain areas, in cells intensely labeled for cytoplasmic p-elF2c[alpha], there was intense fluorescence for c-Jun in the nucleus. Thus, p-elF2[alpha], which is pivotal in the initiation of global protein translation, and its downstream product, the leucine zipper protein, c-Jun, are increased in the mammalian APC within the time frame necessary for the behavioral response. We suggest that p-elF2c[alpha] and c-Jun participate in signaling nutrient deficiency in the IAA-sensitive neurons of the APC. KEY WORDS: * nutrient sensor * translation initiation * feeding behavior * essential amino acids * c-Jun

Omnivores show recognition of essential (indispensable) amino acid deficiency by changing their feeding behavior within 20 min, yet the cellular mechanisms of amino acid sensation in eukaryotes are poorly understood. The anterior piriform cortex (APC) of the brain in rats or its analog in birds likely houses the in vivo amino acid chemosensor. Because amino acid transporters adapt rapidly to essential amino acid deficiency in several cell models, we hypothesized that activation of electrogenic amino acid transport in APC neurons might contribute to the function of the amino acid sensor. We evaluated transport systems in primary cultures of neurons from the APC, hippocampus and cerebellum, or glia, incubated in complete or threonine-devoid (deficient) medium. After 10 min in deficient medium, uptake of threonine or a system A-selective substrate, methyl amino-isobutyric acid, was increased 60% in APC neurons only (P < 0.05). These results demonstrated upregulation of system A, an electrogenic amino acid-sodium symporter. This depletion-induced activation required sodium, intact intracellular trafficking, and phosphorylation of signal transduction-related kinases. Efflux studies showed that other transporter types were functional in the APC; they appeared to be altered dynamically in threonine-deficient cells in response to rapid increases in system A activity. The present data provided support for the chemical sensitivity of the APC and its role as the brain area housing the indispensable amino acid chemosensor. They also showed a region-specific, phosphorylation-dependent activation of the system A transporter in the brain in response to threonine deficiency. KEY WORDS: * deficiency * nutrient sensor * brain * amino acid * neuron culture

A high-speed hybrid optical-digital correlator system was designed, constructed, modeled, and demonstrated experimentally. This correlator is capable of operation at approximately 3000 correlations/s. The input scene is digitized at a resolution of 512 x 512 pixels and the phase information of the two-dimensional fast Fourier transform calculated and displayed in the correlator filter plane at normal video frame rates. High-fidelity reference template images are stored in a phase-conjugating optical memory placed at the nominal input plane of the correlator and reconstructed with a high-speed acousto-optic scanner; this allows for cross correlation of the entire reference data set with the input scene within one frame period. A high-speed CCD camera is used to capture the correlation-plane image, and rapid correlation-plane processing is achieved with a parallel processing architecture.

A simulation and experimental investigation of a recently proposed, compact, phase-conjugating correlator is undertaken. The effects of noise and other distortions in the input image and in the correlator filter plane are considered. As with other phase-only designs, the phase-conjugating correlator is sensitive to distortion of the input image while being robust in the presence of filter-plane distortions; this robustness is enhanced by the phase-conjugating property of the design.

This paper reports on measurements of radial jets using a laser-doppler anemometer and compares the mixing efficiency of a single radial jet with that of a single round jet under buoyant conditions based on experimental data. Dimensional analysis yields two parameters for the calculation of initial dilutions of jets and buoyant plumes. It is noticed that initial dilution of radial jets is much higher than that of round jets having the same source discharge, source buoyancy flux, outlet velocity and area because of intensive entrainment of the radial jet in the zone near the discharge point. Theoretical analysis indicates that the central velocity of the radial jet decays with jet path at a rate of -n (n [greater than] 1), the value of which is proportional to the relative turbulence intensity and hence is related to the geometry of the radial jet. Experimental results show that in most situations, the value of n is approximately 1.5. Measurements also show that the ratio of half-width to distance from the virtual origin of the radial jet is given by [b.sub.w]/[r.sub.0] = 0.101 which is close to that of round jets. However velocity profiles of the radial jet are not completely similar, although the entrainment coefficient is basically a constant of 0.102. These results can help to predict correctly the flow field of the radial jet and its initial dilution.

A one-dimensional numerical model describing the internal hydraulics of tunneled sea outfalls is reported. It includes some local two-dimensional techniques to take the effects of buoyancy and stratified flow into account based on an understanding of purging and intrusion phenomena. The model was verified with data collected from laboratory experiments. Effects of varying configuration, geometry, and hydrograph have been investigated in the model. It is concluded that head loss at riser ports, tunnel angle of inclination, and change in elevation of riser tops have significant effects on purging and intrusion characteristics. Any factor causing uneven velocity distribution among risers makes the system much more prone to intrusion. The operation hydrograph is an important factor affecting purging behavior.

A paper by Gow and Kember suggesting that higher education does not promote independent learning and that students' use of deeper cognitive processes diminishes during higher education is criticized for not considering the method, frequency, and perceived importance of evaluation and grading practices more thoroughly. Authors of the original paper respond. (MSE)

Field tests were performed on a small marine outfall discharging domestic wastes. Dye was injected into the effluent flow entering the pump house and samples were taken in the sump and offshore in the sewage boil. Dilutions were evaluated from the sample concentrations and compared with theoretical predictions. Data were first collected with the outfall discharging freely in the horizontal direction. Following these tests a mixing tube was attached to the outfall. This consisted of a horizontal cylinder designed to provide some predilution before the effluent jet entered the receiving water. Data were again collected after the mixing tube was installed and the dilutions measured were compared with theoretical predictions. These showed that the theory used for the mixing tube under-predicted measured values by more than 25%.

An experimental study of selective withdrawal using intakes in partially submerged structures is described. This study examines circular intake structures located in two layer-stratified bodies of still water. Results are presented for horizontally and vertically oriented intake ports and for a peripheral gap extending around the circumference of the intake structure. Data are compared with submerged, uncapped intakes and with submerged intakes provided with a velocity cap.

Summary.-Analyses of interpersonal behavior within a borderline population usually focus on object relations variables. In contrast, this preliminary research focuses on the nature of attachment styles and its relation to behavioral pathology. 24 hospitalized borderline patients were administered an Attachment Style Inventory and Millon Clinical Multiaxial Inventory. Analysis confirms predicted differences in attachment style between the borderline and normal control samples as well as indicates that a dependent style of attachment within this borderline sample is associated with less pathology than an avoidant, hostile, or resistant/ambivalent style. The implications of this preliminary work for full-scale research are addressed.